"Stay down on the ground if there is a lot of smoke on top and always make sure you're not breathing that air," she said.

"She immediately gathered them up together and got them out of the apartment and called 911," said Mark Brady of Prince George's County Fire and Rescue "And she had stated to us that she had learned that in school during a firefighter visit."

She likely kept her brother and sister from being seriously injured or worse by getting them out of the apartment, fire officials said.

"Our experience is that children, especially children that age, can tend to freeze, or even hide, in a fire situation unlike an adult's instinct, which is to get out," Brady said.

When firefighters arrived at the building in the 9900 block of Good Luck Road about 6:40 a.m. were called to in Lanham, Maryland, about 6:40 a.m., they found fire moving to the upper floors from the terrace level.

Some residents trapped on upper floors had to be rescued from their balconies, Brady said.